Chapter 11, Problem 8STP

Interpretation Introduction

Interpretation: The elements need to be arranged on the basis of increasing ionization energy.

Concept interpretation:Ionization energy is the amount of energy required to remove an electron from an outer shell of atom.

Answer to Problem 8STP

Option A is correct, the correct order from smallest to largest is Cs

Explanation of Solution

Ionization energy of an atom increases left to right in a period because the electrons are held tighter and have higher effective nuclear charge. Due to increase in number of electron and shell remains the same. As we move across a period in periodic table, the ionization energy increases because the electrons are much tightly packed to the nucleus due to high effective nuclear charge.

Conclusion

Other options don’t follow the periodic trends for ionization energy.